Division of Compensation Analysis and 

Support

Program Evaluation Report

Document Number: DCAS-PER-060

Effective Date: 4/27/2015

Revision No. 0

Blockson Chemical Company Page 1 of 2

Author: Signature on file Date: 4/27/2015 

 Dave Allen, HP Team Leader

Approval: Signature on file Date: 4/27/2015 

 J.W. Neton, Associate Director for Science

Supersedes: None

RECORD OF ISSUE/REVISIONS

ISSUE 

AUTHORIZATION 

DATE

4/27/2015

EFFECTIVE 

DATE

4/27/2015

REV. NO. 

0

DESCRIPTION

New document to determine the effect of 

the revised Technical Basis Document 

for the Blockson Chemical Company on 

previously completed claims.

1.0 Description

Revision 4 of the Technical Basis Document (TBD) for the Blockson Chemical Company 

(DCAS-TKBS-0002) was issued on 5/19/2014. The previous revision (revision 3) was 

issued on 12/20/2010. A Program Evaluation Report (DCAS-PER-036) was issued on 

4/5/2012 to evaluate the effect of revision 3 on previously completed claims. This PER 

(DCAS-PER-060) will evaluate the effect of revision 4 of the TBD on previously 

completed claims.

2.0 Issue Evaluation

Revision 4 of the TBD changed the way internal dose was estimated for the stomach, 

small intestine, upper large intestine, lower large intestine, and colon. Both revision 3 

and 4 provide inhalation and ingestion intakes for building 55. Revision 3 indicated that 

ingestion intakes produce a higher dose in the gastrointestinal tract. While this is true in 

many cases, some exposure situations result in the inhalation intakes producing higher 

doses in these organs. Therefore, revision 4 of the TBD was issued to change the 

instructions to use the intake that produces the higher dose.

3.0 Plan for Resolution or Corrective Action

In order to evaluate the effect of revision 4 of the TBD on previously completed claims, a 

search was conducted for all completed claims that had a probability of causation (POC) 

of less than 50% and an internal dose target organ of stomach, small intestine, upper large 

intestine, lower large intestine, or colon. This search identified 23 claims. Sixteen of 
Division of Compensation Analysis and 

Support

Program Evaluation Plan

Document Number: DCAS-PER-060

Effective Date: 4/27/2015 Revision No. 0 Page 2 of 2

these claims had previously met the conditions for compensation under a Special 

Exposure Cohort (SEC) and did not have an additional non-SEC cancer. One of the 

remaining 7 claims had been completed using revision 4 of the TBD and was removed 

from further evaluation.

For the remaining 6 claims, the internal dose was calculated using the inhalation and 

ingestion intakes in revision 4 and the higher of the two selected. This dose was then 

compared to the internal dose in the current dose reconstruction. The comparison 

reviewed the total internal dose for all years dose was assigned as well as the highest year 

of internal dose. Revision 4 resulted in a higher internal dose for only one of the 6 

claims. This evaluation was considered complete for the remaining 5 claims.

For the one claim resulting in a higher internal dose, a full dose estimate was completed 

using TBD revision 4, as well as all applicable approved dose reconstruction methods. 

The POC remained below 45% for this claim. Therefore no claims need to be returned to 

NIOSH. NIOSH will provide DOL with the list of all the claims evaluated under this PER.